IM28.8-10 | Obstructive Airway Disease Clinical Evaluation — Summary & Reflection

KEY TAKEAWAYS

Clinical evaluation of obstructive airway disease is a three-part skill: history, examination, and differential diagnosis.

History: Characterise symptoms by onset, pattern, triggers, severity (MRC grade, exercise tolerance), and response to bronchodilators. Asthma = episodic, nocturnal/morning, triggers-based, atopic, reversible; COPD = progressive, daily sputum, smoking history (pack-years), biomass fuel exposure, exacerbation frequency.

Examination: Systematically: RR + SpO₂ → inspection (barrel chest, accessory muscles, cyanosis, pursed-lip breathing) → trachea central/deviated → percussion (resonant/hyper-resonant/dull/stony dull) → auscultation (prolonged expiratory phase, wheeze character, air entry, crackles). Silent chest = emergency (insufficient airflow for wheeze). Normal PaCO₂ in breathless asthmatic = near-fatal sign.

Specific signs: Consolidation = dullness + bronchial breathing + crackles + increased VR. Effusion = stony dullness + absent breath sounds + horizontal upper border. Pneumothorax = hyper-resonance + absent breath sounds + tracheal deviation away. Cor pulmonale = raised JVP + right ventricular heave + peripheral oedema.

Differential priorities: Young + atopy + episodic + reversible → asthma. Old + smoker + progressive → COPD. Elevated JVP + crackles + acute onset → cardiac failure. Unilateral signs + sudden onset → pneumothorax. Fever + dullness + bronchial breathing → pneumonia.

REFLECT

Consider the two patients from the opening hook. The 24-year-old woman with episodic nocturnal wheeze and the 62-year-old farmer with progressive dyspnoea are both 'breathless with wheeze' — but every element of their clinical evaluation is different. Reflect on this: when you face a breathless patient for the first time, what is the single most important question you would ask in the first 30 seconds — and how does the answer immediately direct your examination priorities? Also consider: what are the consequences of misclassifying a left ventricular failure patient as asthma and giving high-dose bronchodilators without diuretics? How does this reinforce the principle that differential diagnosis is not an academic exercise but a patient safety requirement?